This application claims priority to Japanese patent application No. 2000-270470, filed on Sep. 6, 2000, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a vehicle body structure capable of reducing the overall length of a tricycle.
2. Description of Background Art
A vehicle body structure of a tricycle, in which a front vehicle body fitted with a front wheel and a rear vehicle body fitted with rear wheels are rollably connected to each other by a connecting portion, has been disclosed in Japanese Patent Publication No. Hei 1-23356, entitled xe2x80x9cParking Lock Device for Oscillation Type Tricyclexe2x80x9d.
FIGS. 1 and 2 of the above-mentioned publication are re-printed herein as FIGS. 16 and 17 of the present invention. A description will now be provided with reference to FIGS. 16 and 17 of the present invention. FIG. 16 of the present invention illustrates a major part of the original FIG. 1. It should be noted that the reference symbols in FIGS. 16 and 17 do not correspond with the above-mentioned publication.
FIG. 16 is a side view of a major part of a tricycle according to the background art. An oscillation type tricycle 200 comprises a front vehicle body 201 on the front wheel side and a rear vehicle body 202 on the rear wheel side, which constitute the vehicle body. Fitting boss portions 204, 204 (fitting boss portion 204 on the far side is not shown) of an oscillating joint 203 are vertically movably fitted to a rear portion of a lower portion of the front vehicle body 201 by a pin 206. A rear frame 207 is fitted to a rear portion of the oscillating joint 203. Furthermore, rear wheels 208 are fitted to the side of the rear wheel 207. Accordingly, the front vehicle body 201 and the rear vehicle body 202 can be relatively rolled by the oscillating joint 203.
FIG. 17 is a sectional view showing the oscillating joint according to the background art. A support shaft 212 is rollably fitted to a lower case 211 and an upper case (not shown) of the oscillating joint 203. A roll lock mechanism 213 for restricting relative rotation of the case side (lower case 211 and upper case) and the support shaft 212 is provided at the front side of the support shaft 212. Fitting boss portions 204, 205 are disposed at the front end of the lower case 211 through arms 214, 215. The rear frame 207 is fitted to a rear portion of the support shaft 212. Furthermore, an operating cable 216 for operating the roll lock mechanism 213 and locking (braking) the rear wheels 208 is laid from the front vehicle body 201 to the rear vehicle body 202 through the oscillating joint 203. It should be noted that each component of the xe2x80x9croll lock mechanism 213xe2x80x9d is disclosed in FIG. 2 of the above-mentioned publication, but the term xe2x80x9croll lock mechanism 213xe2x80x9d is newly added for the convenience of description.
In FIG. 17, the oscillating joint 203 is so constructed that the roll lock mechanism 213 is disposed on the front side of the support shaft 212, the arms 214, 215 are extended to the front side of the vehicle from the lower case 211, and the fitting boss portions 204, 205 are provided at the front ends of the arms 214, 215. Accordingly, the length of the oscillating joint 203 in the front-rear direction of the vehicle is increased. As a result, the spacing between the front vehicle body 201 and the rear vehicle body 202 shown in FIG. 16 is increased. Accordingly, the overall length of the tricycle is increased.
The tricycle 200 is typically used for delivery purposes. Therefore, the tricycle 200 would be used in narrow alleys. Accordingly, those having a small overall length and capable of making sharp turns are desirable.
Accordingly, an object of the present invention is to provide a vehicle body structure of a tricycle, which can reduce the overall length of the tricycle.
In order to attain the above object, according to a first aspect of the present invention, a vehicle body structure of a tricycle comprises a front vehicle body fitted with a front wheel, a rear vehicle body fitted with rear wheels, and a connecting portion by which the front vehicle body and the rear vehicle body are relatively rollably connected to each other, wherein the connecting portion comprises a flange, a shaft extended from the flange, and a bearing fitted to the shaft, and the flange is fitted to a rear portion of the front vehicle body, whereas the bearing side of the connecting portion is fitted to the rear vehicle body.
In the above construction, the shaft is extended from the flange, whereby the connecting portion is made to be shorter than in the background art. Accordingly, a reduction in the overall length of the tricycle is obtained.
According to a second aspect of the present invention, a vehicle body structure of a tricycle comprises a front vehicle body fitted with a front wheel, a rear vehicle body fitted with rear wheels, and a connecting portion in which the front vehicle body and the rear vehicle body are connected through a shaft extending substantially in the front-rear direction of the vehicle and a bearing, the front vehicle body and the rear vehicle body being relatively rollably connected to each other by the connecting portion, wherein a roll lock mechanism for restricting relative rotation of the shaft and the bearing is disposed on a lateral side of the shaft, and a fitting portion for fitting the rear vehicle body to the bearing is provided on a side of the bearing.
Since the roll lock mechanism is disposed on a lateral side of the shaft, the connecting portion is made shorter than in the background art in which the roll lock mechanism is disposed on an extension of the shaft and the distance between the front vehicle body and the rear vehicle body is reduced. Accordingly, a reduction in the overall length of the tricycle is obtained. Furthermore, the turning performance of the tricycle is enhanced.
In addition, the fitting portion for fitting the rear vehicle body is provided on a side of the bearing, and the bearing and the rear vehicle body are overlapped with each other. Accordingly, the overall length of the tricycle can be further reduced.
According to a third aspect of the present invention, the roll lock mechanism comprises an arm-like or flange-like side projecting member projecting sideways from the shaft, a lock member swingably fitted on the side of the bearing to be engaged with a recess and projection portion provided on the side projecting member, and a cable fitting portion provided at an end portion of the lock member so as to fit a cable for swinging the lock member.
Since the side projecting member projects sideways from the shaft, the lock member and the cable can be located at such positions as not to interfere with the shaft, and the degree of freedom in laying out the roll lock mechanism and the cable can be enhanced. Therefore, the roll lock mechanism and the cable can be disposed at appropriate spaces according to the shape and size of the front and rear vehicle bodies and accessories fitted to the front and rear vehicle bodies.
According to a fourth aspect of the present invention, the rear vehicle body is provided with a rear wheel lock mechanism for locking the rear wheels, the front vehicle body is provided with a parking lever for operating the rear wheel lock mechanism, and a front half portion of the cable is laid between the parking lever and the rear wheel lock mechanism, whereas a rear half portion of the cable is laid between the rear wheel lock mechanism and the roll lock mechanism.
Since the front half portion of the cable is laid between the front vehicle body and the rear vehicle body, torsion of the cable due to the relative rolling of the front vehicle body and the rear vehicle body is absorbed in a larger distance as compared with the background art. Accordingly, an unnecessary burden is not applied to the cable. Furthermore, the cable becomes advantageous with regard to bending. Accordingly, replacement of the cable or the like is reduced, and maintenance cost of the tricycle can be suppressed.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.